Drying of pulp



Nov. 19, 1963 F. o. HELVERSEN DRYING OF PULP 3 Sheets-Sheet 1 Filed Aug.31, 1961 INVENTOR. Frederick D. Helversen F I g. 2 BY Attorneys Nov. 19,1963 F. D. HELVERSEN DRYING 0F PULP :5 Sheets-Sheet 2 Filed Aug. 31,1961 JNVENTOR. P Frederick D. Helversen Attorneys Nov. 19, 1963 F. D.HELVERSEN DRYING OF PULP 3 Sheets-Sheet 3 Filed Aug. 31. 1961 uvvnvron.Frederick D. Helversen mew Mum.

Attorneys United States Patent 3,111,453 DRYING 0F PULP Frederick D.Helversen, Burlingame, Califl, assignor to Crown Zellerbach Corporation,San Francisco, Calif., a corporation of Nevada Filed Aug. 31, 1961, Ser.No. 135,168 9 Claims. (Cl. 162-201) This invention relates to thepreparation of a product for shipment by removing excess moisturetherefrom to reduce the products shipping weight and bulk. Moreparticularly, this invention relates to the dewatering and drying of amoist product so that the major portion of the water in such product isremoved therefrom during preparation of the product for shipment. lnaddition to lowering the shipping weight of the product, the removal ofmoisture also enhances the product by precluding deterioration of thesame during shipment and storage.

Still more particularly, this invention relates to the dewatering anddrying of a fibrous product, such as wood or similar pulps used in themanufacture of paper, for the purpose of reducing the shipping bulk andweight of the pulp and precluding deterioration thereof. In this regard,the drying procedure involved in this invention includes the compressingor compacting of fibrous products such as wood pulp into tubularsections of hollow, generally cylindrical configuration, each of whichhas a longitudinal opening therethrough. This compacting results in aninitial dewatering of the product but the compacted product stillcontains appreciable moisture. Such compacted sections may readily beair dried to further reduce their moisture content in that, during asubsequent drying operation, quantities of drying air may pass not onlyall around the sections but also through the longitudinal openingsextending therethrough.

In the manufacture of pap-er, timber cut in forests is delivered to apulp mill adjacent the timber site where the timber is reduced by anyone of several well known methods to pulp, which comprises thecellulosic fibers from which paper ultimately is produced. In manyinstances, the paper manufacturing mill u's located adjacent the site ofthe pulp mill and a slurry of pulp and water is conveyed in any suitablemanner directly from the pulp mill to a paper making machine in theadjacent paper mill.

However, it has proved economically desirable in some situations tolocate paper mills in industrial areas closer to the market for thepaper and the various products into which the paper subsequently is tobe converted. Because the timber forests and pulp mills generally arelocated at substantial distances from the ultimate paper market, theshipment of pulp over long distances by boat, truck or rail frequentlyis required.

Accordingly, because shipping charges generally are determined by Weightand/ or bulk, reduction of the bulk and weight of the pulp temporarilyfor shipment and handling is highly desirable in that the substantialamounts of moisture carried in raw pulp unnecessarily increases itsshipping cost without producing any substantial advantages.

This invention is directed principally to the dewatering and drying ofwood pulp to reduce its bulk and moisture content to a relatively lowlevel so that the same may readily and economically be transported byrail, truck or ship without paying shipping charges for useless water insuch pulp.

Following shipment of dried pulp to a distant paper mill, the pulpsubsequently has water added to it to again form a pulp slurry readilyhandled in a paper machine in the conventional and well known manner.Because some time may pass before the dried pulp has water added3,111,453 Patented Nov. 19, 1963 thereto, its low moisture contentretards deterioration thereof during shipment and storage.

In line with the purposes of this invention, it is desired that thedewatered and dried pulp be in a convenient form for drying andshipment, and for this purpose the aforementioned hollow tubularsections mentioned have proved highly effective.

While hereinafter reference will be directed primarily to the dewateringand drying of fibrous wood pulp intended for the manufacture of paper,it should be understood that this invention is applicable to thetreatment of other compressible products in which excess moisturepresents a problem. Accordingly, while the invention has particularutility in and is directed to the treatment of wood pulp as hereinafterspecifically described, it should be interpreted in light of its broaderaspects.

In co-pending application Serial No. 842,269, filed September 25, 1959,now US. Patent No. 3,021,254, entitled Method and Apparatus forDewatering Pulp and the Resulting Product, a method and an apparatus aredisclosed for removing by compression a substantial portion of themoisture from a fibrous product, such as wood pulp. However, the pulpproduct treated in the manner of the co-pending application stillcontains a substantial quantity of moisture.

The present invention relates to the further treatment of compressed andcompacted pulp sections of the type disclosed in such co-pendingapplication to further remove the greater portion of the moistureremaining in the compressed pulp after compaction thereof. For thepurposes of this invention, it is preferred that the moisture content ofthe dried pulp treated be reduced to 10% or below, with a moisturecontent of 6-8% being readily and economically obtainable by employingthe method of this invention.

With further regard to the compacting of pulp in the manner disclosed inthe co-pending application, the pulp is compacted into hollow tubular,generally cylindrical sections or segments. Further drying of suchsections in the manner of this invention is enhanced due to the factthat drying air may pass not only around the sections but alsointernally of the sections through the longitudinal openings therein.

Preferably large piles of compacted and dewatered sections arepositioned on a suitable supporting surface and a quantity ofsubstantially dry air, which may be heated or unheated as preferred, isforced through the pile. Such air during its travel through the pilefollows a tortuous, highly irregular path through and around therespective pulp sections so that, upon continuing air flow for apredetermined time, the average moisture content of the pulp sectionsmay be reduced to a practical level.

With the foregoing in mind, it should be understood that objects of thepresent invention include the provision of a method for dewatering anddrying a product, such as fibrous wood pulp; the provision of structuralmeans in which such method may be carried out effectively; the provisionof components in combination with such structural means for facilitatingthe convenient handling of large quantities of pulp sections during thedrying procedure; and the provision of a method and means for air dryingpiles of generally cylindrical hollow tubular pulp sections.

These and other objects will become apparent from a study of thefollowing specifiication, in which reference is directed to theaccompanying drawings.

FIG. 1 is an isometric, generally schematic view of the structuralbuilding means of this invention in which a product drying operation maybe carried out;

FIG. 2. is a plan view of the supporting surface of the structure ofFIG. 1;

FIG. 3 is a vertical sectional view through the building structure takenin the plane of line 33 of FIG. 2;

FIG. 4 is a partial vertical section through the supporting surface slabof the building structure of the area defined by line 44 of FIG. 3;

FIG. 5 is a vertical sectional view through the supporting surface slabtaken in the plane of line 5-5 of FIG. 4;

FIG. 6 is an isometric view of means provided in conjunction with anoverhead conveyor of the building structure for diverting compacted pulpsections from the conveyor onto a predetermined portion of thesupporting surface slab;

FIG. 7 is a vertical section through an apparatus for continuouslycompacting and forming tubular generally cylindrical sections ofdewatered pulp; and

FIG. 8 is an isometric view of a compacted and dewatered pulp tubularsection formable by the apparatus of FIG. 7.

With the apparatus shown in FIG. 7, the initial dewatering of a fibrousproduct such as wood pulp may be economically and expediently effectedso that a dewatered product of lighter weight and lower bulk having atubular configuration is provided which enhances further drying ashereinaftter discussed. Such pulp sections may be easily handled duringfurther drying and may be transported conveniently and re-pulped by thesubsequent addition of water thereto in preparation for the paper makingoperation.

Specific reference is first directed to FIG. 7 which shows oneembodiment of the apparatus of the co-pending application by whichgenerally cylindrical hollow tubular pulp sections or segments 1 of thetype shown in FIG. 8 may be produced. For a full discussion andunderstanding of such apparatus, reference is directed to saidco-pending application. For the purposes of this invention, however, theapparatus for producing tubular pulp sections in continuous fashion froma substantially continuous supply of pulp slurry will be brieflydescribed.

Such apparatus includes a pulp slurry hopper 2 suspended in any suitablefashion, such as by a series of bolts 3, from a supporting tablestructure 4 provided with a central opening 6 therein. Through suchopening a reciprocatable piston or plunger 7 is positioned which extendsthrough an opening 8 in a tubular extension 9 of plate 11 which formsthe top of the pulp slurry hopper 2. Preferably a leak preventing O-ringis provided in plate 11 to preclude leakage around the periphery ofplunger 7 during reciprocation thereof.

In the embodiment illustrated, plunger 7 is provided with a longitudinalfluid passageway 13. Above table 4, a fitting 14 is secured to theplunger in registry with the upper end of passageway 13. A flexible tube16 is connected to such fitting for taking off water from thepassageway.

Any suitable means (not shown) may be employed for reciprocating theplunger in a generally vertical direction as indicated by the arrows. InFIG. 7, the plunger is shown at the bottom of its vertical stroke.

Provided in conjunction with hopper 2 is an inlet conduit 17 throughwhich a continuous supply of pulp slurry is introduced into the hopper.A container 18 having an internal chamber is bolted or otherwise securedin depending fashion from the bottom of hopper 2. A perforate tube 19having a series of moisture passage holes 20 therethrough depends fromthe cover plate 21 of such container. Threadedly connected to the lowerend of tube 19 is a tubular extension 22, which preferably has aninternal taper of a predetermined amount for the purpose described inthe co-pending application. A series of radial openings in the form oflongitudinal slots 23 are provided through the wall of tubular extension22 to permit the passage of moisture therethrough into the chamber ofcontainer 18.

At its lower end 24, tube extension 22 projects in leak- 4 proof fashionthrough the bottom of container 18. Adjacent its bottom, container 18has a fiuid removal outlet conduit 26 through which water passingoutwardly through the tube 19 and the extension 22 into the chamber ofcontainer 18 may be withdrawn from the apparatus. Because of thesubstantial pressures applied to the tapered tube extension 22 duringthe pulp dewatering process, preferably a re-enforcing band 27 issecured about the outer periphery of the tube extension to strengthenthe same.

At its lower end plunger 7 is provided with a substantially planar pulpcompressing surface 28 and an axially aligned rod 29 is threadedlyengaged with the plunger to depend from such surface. Rod 29 also isprovided with a longitudinal internal passageway 31 which extends for apredetermined portion of the rod and is in alignment with the passageway13 provided in plunger 7. Rod 29 also is provided with a perforate wallhaving a series of radial water passage openings 32 spacedly providedtherein.

From the foregoing it should be understood that, upon reciprocation ofthe plunger upwardly from the position shown in FIG. 7, the compactingsurface 28 of the plunger will be raised above the top of container 18into the hopper so that pulp slurry in the hopper may enter the tube 19and flow therethrough into the tube and its extension 22. Thereafter,upon reciprocation of the plunger downwardly, slurry in the tube will becompacted therein and water in the slurry will be forced outwardlythrough the perforate wall of tube 19 and through the slots 23 in thetubular extension 22.

Upon repeated high speed reciprocation of the plunger, a substantiallycontinuous length 1 of compacted pulp will be extruded from the lowerend 24 of the tube extension 22 as seen in dotted lines in FIG. 7. Rod29 used in conjunction with the plunger results in the length ofcompacted pulp being of hollow tubular configuration. During reciprocation of the plunger, the length of compacted pulp is broken off inrandom lengths or segments, each of which has a generally cylindricalouter periphery and a generally cylindrical opening through the interiorthereof as seen in FIG. 8. It it such dewatered and compacted pulpsegments that are further dried by this invention.

The water removed from the pulp during the compacting operation whichpasses outwardly through tube 19 and its extension 22 is withdrawn fromcontainer 18 through outlet 26, while water passing inwardly into therod 29 is withdrawn upwardly through aligned passageways 31 and 13through tube 16.

As noted previously, during the dewatering and compacting operation, themoisture content of the pulp is appreciably reduced. In this regard, ithas been found possible on a practical basis to reduce the moisturecontent below preferably 40-60% moisture, with 50% being the approximateaverage moisture content of the compacted pulp sections.

Following the dewatering operation, the pulp sections are furthertreated to substantially dry the same by removing the majority ofremaining moisture therefrom so that the sections may be economicallyshipped or stored without deterioration. As noted previously, it ispossible, on a practical and economical basis, to dry the pulp sectionsto a moisture content of well below 10%.

The formation of the dewatered pulp into compacted tubular sections orsegments of ring-like or doughnut shape is an important feature of thisinvention, in that the configuration of the sections greatly facilitatesthe subsequent drying thereof. With the compacted masses produced withthe apparatus and method of the aforementioned application, the waterremoval may expeditiously be effected to substantially any leveldesired.

The small amount of moisture remaining in the pulp after the dryingoperation has been found to be not detrimental to the problem ofdeterioration, nor is the same prohibitive from the shipping coststandpoint. Removal of substantially all moisture from the pulp, whilepossible with this invention, has been found to be not economicallyfeasible.

Because of the hollow tubular configuration of the pulp sections orsegments produced by the apparatus of FIG. 7, the same may be readilyand rapidly dried in quantity by positioning large numbers of thesections on a supporting surface in random arrangement so that a streamof drying air may be forced over such pile. In this connection, the airemployed preferably should be substantially dry, and may be heated ifheating of the same is economically feasible. However, unheated ambientair has been found to be suitable so long as the humidity of the air isrelatively low.

Preferably the drying air is forced upwardly through a large pile ofpulp sections positioned in random arrangement on a supporting surfaceas seen in FIG. 4. This results in the drying air taking a tortuous andhighly irregular path over the individual pulp sections and through thelongitudinal openings in the respective sections. In this manner highlyeffective pulp drying may be effected.

Because the walls of the respective pulp sections are relatively thin,the drying air is effective to withdraw moisture both radially inwardlyand outwardly relative to such walls to rapidly lower the moisturecontent of the sections to the level found economically practical.

For effecting drying of pulp in tubular sections, as described, means inthe form of a special building structure has been devised. Such buildingstructure is illustrated in FIGS. 1 through 6, and includes an elongatedsupporting slab 36, preferably of concrete. Provided in such supportingslab is a network of air ducts, generally designated 37. Such ductnetwork includes a series of spaced transverse conduits 38 positioned atpredetermined intervals along the lentgh of slab 36, as best seen inFIG. 2. Each of the transverse conduits has in communication therewith aseries of laterally spaced vertical extensions 39 positioned across thewidth of the slab, as best seen in FIG. 3.

Each of the vertical duct extensions opens into one of a series oflongitudinal conduits 41, each of which is open to the top of supportingsurface 42 of the concrete slab. A series of elongated metal grillsections 43 are supported over each longitudinal conduit 41 to precludethe passage of pulp sections into the conduit, as best seen in FIG. 4.Any suitable means may be provided for introducing drying air into thetransverse conduits 38, and in the embodiment shown in the drawings, apump 46, as seen in FIG. 3, is provided in conjunction with each suchtransverse conduit. Each pump forces ambient air, or heated air ifeconomically feasible, into the duct network under pressure through thetransvers conduits 38 and therefrom into each of the longitudinalconduits 41.

Preferably valve means are provided in conjunction with the longitudinalconduits 41 for directing the air flow therethrough in a selectivemanner, as may be desired. In this regard, attention is directed toFIGS. 4 and 5 which illustrate such valve means. A plurality of parallelvalve actuating rods 47 extend transversely of the supporting slab inspaced relationship. Each rod is generally aligned with a transverseconduit 38 and is journaled in the cement slab 36, as at 48, betweenadjacent longitudinal conduits 41. A plurality of valve vanes 49 aresecured to each rod for rotation therewith, with one vane being locatedin each longitudinal conduit above a vertical duct extension 39, as seenin FIG. 5.

Upon rotation of a rod 47 in the clockwise direction as viewed in FIG.5, each vane is rotated to the position shown so that the flow of airupwardly through the conduit extension 39 is directed to the left inlongitudinal conduit 41. Rotation of the rod and its associated vanescounter-clockwise results in the air stream being directed to the rightin each longitudinal conduit. Similarly, the air flow may be divertedequally to the left and right depending upon the vane position chosen.

It should be understood that a series of such valve control rods 47 andassociated vanes are spaced along the 6 length of the slab 36. In theembodiment illustrated, each of such rods is actuatable by a controlhandle 50 secured to one end of each rod for rotating the same in aclockwise or counter-clockwise direction as desired. See FIG. 3.

Because it is preferred to protect the pulp sections being dried fromthe elements of nature during the drying operation, a roof structure orenclosure preferably is supported over the pulp supporting slab 36 inany convenient fashion, as shown generally in FIGS. 1 and 3. In theembodiment illustrated, the building roof comprises a simple invertedV-shaped construction defined by spaced structural members 51 secured tofootings 51' in any suitable manner.

Preferably the roof structure is provided with a foundry type ventstructure 52 to permit escape of the drying air from the sturcture afterthe same has passed upwardly through the piles of pulp being dried.Desirably, the building structure is provided adjacent its bottom onopposite sides thereof with a series of hinged doors 53 which may bepivoted upwardly to permit access to the respective actuating arms 50for the valve means and so that other access may be had to the interiorof the building structure as may be required.

Extending along one edge of the supporting slab 36 is a continuousbelt-roller conveyor 56 which may be driven in any suitable well knownmanner. The purpose of such conveyor is to remove dried pulp sectionsfrom the building enclosure after the drying operation is completed, andto transport the same to waiting transportation vehicles.

Supported above the concrete slab 36 in depending relationship from thepeak of the roof structure is an overhead conveyor 57 for feedingdewatered pulp sections to be dried onto the supporting surface.Conveyor 57 may be of any suitable type, but in the generally schematicembodiment illustrated, it comprises a conventional roller typecontinuous belt conveyor. It should be understood that pulp sectionscarried by the overhead conveyor 57 are to be removed therefrom by meansto be described so that the pulp sections may fall onto the supportingsurface to provide a pile of sections to be dried. Dewatcred pulpsections to be dried may be introduced onto the belt of conveyor 57 inany convenient manner.

To divert predetermined quantities of pulp sections onto predeterminedportions of the supporting slab, means are provided in conjunction withconveyor 57, as illustrated generally in FIG. 6, for removing suchsections from the conveyor. While such diverting means may take variousforms, in the embodiment illustrated such means includes a generallyV-shaped plow member 58 mounted for movement on a series of rollers 59engaged with a track 61 secured to opposite sides of the overheadconveyor structure. The plow may be selectively positioned along thelength of the conveyor with the conveyor belt passing therebeneath sothat pulp sectoins carried by the conveyor belt will be plowed from theconveyor belt to fall therefrom in the manner shown in FIG. 1.

Preferably means are provided in conjunction with the diverting plow formaintaining the same in a predetermined position relative to thesupporting slab so that a pile of pulp sections may be built upon aselected portion of a supporting slab. In this regard, the piles of pulp62 produced may be generally discrete and separate from each other, asshown in FIGS. 1 and 2, or a continuous row of pulp sections may bebuilt up for the full length of the supporting slab or any desirableportion thereof.

In the embodiment of the diverting means shown in FIG. 6, thumb screws63 are shown in conjunction with the plow member by means of which theplow member may be secured after the plow has been positioned over apredetermined portion of the rails 61. In this manner, the plow may beprecluded from movement along the conveyor structure. However, the useof manual means such as thumb screws necessitates a worker climbing on a7 ladder or the like to the overhead conveyor structure to engage anddisengage the thumb screws as required.

Accordingly, it is preferred that more automatic means not requiringmanual operation on the overhead conveyor be provided. In this regard,FIG. 6 also shows means for effecting positioning of the diverting plow58 without requiring manual aljustment on the overhead conveyor. In thisconnection, a pair of opposite cables 66 and 67 are secured to oppositeends of the plow. By pulling on cable 66, the plow may be moved to theright of FIG. 6, while pulling an cable 67 will move the plow to theleft. Any automatic or manual means may be employed for effectingmovement of one or both cables to effect positioning of the plow in thelocation desired. Upon positioning the plow in a given location relativeto the supporting slab of the building structure, it should beunderstood that cable 66 thereafter will maintain the plow in suchposition until tension on such cable is released.

Drying air passing through the conduit network 37 in the supporting slab36 will pass upwardly through the respective piles of pulp sections tobe dried in the tortuous path illustrated in FIGS. 3 and 4. Bycontinuing air flow through a given pulp pile for the desired time, themoisture content of the sections may be diminished to any predeterminedpractical level. In this regard, an air flow of approximately 7 to 10cubic feet per minute through each vertical conduit extension 39 issuitable for effecting drying of large piles of products in a relativelyshort time.

As noted previously, the use of substantially dry, unheated ambient airfor purposes of economy is preferred, but, if desired, such air may beheated. An air temperature in the range of l00l50 F. has been foundsuitable for this purpose.

From the foregoing, it should be obvious that, in the absence of theparticular hollow tubular configuration of the respective sections ofpulp to be dried, the procedure described could not be easily effectedin that the tortuous air passages extending through the pile would besubstantially absent.

While this invention relates primarily to the drying of hollow tubularpulp sections to reduce the weight thereof, it should be understoodthat, where shipping costs are also determined on a basis of bulk inaddition to weight, the doughnut shaped sections after drying may bebroken down to further reduce their bulk so that additional savings on abulk basis also may be effected during shipment.

It should be understood that the building structure illustratedpreferably is of substantial size, with the supporting slab and roofstructure shown being up to 1400 feet long and up to 100 feet wide. Insuch a structure, the pulp piles being dried may be up to 40 feet highand 80 feet across at the base.

After drying, the dried piles of pulp may be moved onto the conveyor 56running alongside the supporting slab by any suitable means. Because ofthe size of the building structure, bulldozers or other tractors may beemployed to push the dried pulp onto the conveyor 56 for movement to thetransportation vessels.

If desired, the ends of the building structure may be enclosed topreclude contact of the elements of nature with the pulp sections beingdried.

The length of the drying procedure may vary, depending upon the air flowrate, the size of the piles being treated, the moisture content of thedewatered pulp sections as the same are removed from the apparatus inwhich the same are compacted, the temperature and humidity of the dryingair, and the like. However, by way of example, by employing the forcedair drying procedure described herein on large piles of pulp sectionshaving an initial moisture content in the 40-60% range, the averagemoisture content may be reduced to approximately 8% within a period of72 hours using an unheated air flow rate of from 7-10 cubic feet perminute.

Further treatment over extended periods of time, it has been found, hasbeen generally ineffective to reduce appreciably the moisture contentbelow the above practical level, and the expense of attempting tofurther reduce the moisture content generally is prohibitive in that theweight savings effected thereby does not warrant the additional expense.For example, upon extended treatment of pulp sections dried to the abovelevel for time periods up to 192 hours, the moisture content is reducedan additional amount of less than 1%.

By employing the forced air drying method on pulp sections as described,the drying procedure is much speeded up over conventional air drying,and is relatively inexpensive in that, as noted previously, ambientunheated air may be empoyed so long as the relative humidity of the airthus employed is not appreciable. In this regard, suitable results havebeen obtained with air in which the average relative humidity was ashigh as 40%. Obviously, however, the lower the humidity of the air, themore effective and more rapid will be the drying results produced.

Having thus made a full disclosure of this invention as the same relatesto the drying of compressed products, such as wood pulp and like fibrousmaterials, reference is directed to the appended claims for the scope tobe afforded thereto. In this regard, it should be understood thatmodifications to this invention which may become apparent to one skilledin the art after reference has been taken to this specification arecontemplated as falling within the scope hereof.

I claim:

1. A method of drying a wet fibrous product comprising compacting saidproduct into hollow tubular sections to remove a determinable part ofthe moisture therefrom, each of said sections comprising a wall defininga longitudinal opening therethrough, piling a plurality of said tubularsections in random arrangement on each other, and forcing a stream ofdrying air against a plurality of said sections when thus piled on eachother whereby said air stream passes in a tortuous path over saidsections and through the longitudinal openings therein to remove themajor part of the moisture remaining in said sections after compactingthereof.

2. A method of drying fibrous wood pulp to prepare the same fortransportation, comprising compacting a mass of said pulp under pressureinto a plurality of hollow tubular sections to lower the moisturecontent of the pulp thus compacted to within the range of 40'60%, pilinga plurality of said compacted sections in random arrangement on eachother, forcing a stream of drying air against such pile of sectionswhereby said air travels in a tortuous path and passes over and throughindividual sections during its travel through said pile, and continuingsuch air flow through said pile until the average moisture content ofsaid sections is diminished thereby to below 10%.

3. A method of preparing wood pulp for shipment by reducing the moisturecontent thereof, comprising compacting a quantity of wood pulp into aplurality of hollow compacted pulp sections each of which has agenerally cylindrical wall defining a longitudinal opening therethrough,piling a large number of said sections in random arrangement on eachother on a supporting surface, providing means for forcing a stream ofrelatively dry air upwardly through such pile of sections, forcing saidstream of air through said pile of sections whereby said air movesthrough said pile in a tortuous path through and around individualsections, and continuing such air flow until the average moisturecontent of said sections is reduced to approximately a predeterminedlevel.

4. The method of claim 3 which includes positioning said pile within anenclosure during the drying operation to protect said sections from theelements of nature during drying.

5. A method of drying wood pulp to preclude deterioration of saidsections and to reduce the weight thereof for shipment, comprisingcompacting said Wood pulp into a plurality of partially dewateredtubular sections, each of said dewatered sections having a moisturecontent within the general range of 4060%, providing a supportingsurface having a network of air ducts opening thereinto, positioninglarge quantities of said sections in random arrangement on saidsupporting surface whereby a large area of said surface is covered by apile of said sections, forcing a volume of generally dry air throughsaid duct network and upwardly through said pile whereby largequantities of said air are forced in a tortuous path through and overindividual sections in said pile, and continuing forcing said airthrough said pile until the average moisture content of said sections isreduced to below 6. A method of drying wood pulp to be used in papermaking to obviate pulp deterioration and to prepare the same forshipment by reducing its weight, comprising compressing a supply of highwater content pulp into hollow generally cylindrical tubular sections inwhich the pulp fibers are closely compacted and the pulp water contentis reduced to below 70%, after compressing piling a quantity of saidtubular sections in random fashion over a source of drying air, forcinga substantially continuous stream of said air upwardly through saidsections whereby said air passes in an irregular tortuous path throughand around individual sections of such pile, and continuing forcing saidair stream through said pile until the average water content of thesections in said pile is reduced to below 10%.

7. A method of dewatering and preparing fibrous wood pulp for shipmentcomprising providing a supply of pulp slurry, compacting the pulp fibersof said slurry into a hollow tubular body having a longitudinal openingtherethrough, the moisture content of said body being substantiallydecreased during said compacting, separating said body into a pluralityof relatively short generally cylindrical segments, piling a pluralityof said segments on each other in other arrangement on a supportingsurface, and forcing a stream of drying air through such pile ofsegments whereby said air passes over and through the individualsegments of said pile to further reduce the moisture content thereof.

8. A method of drying quantities of a wet product, said product being inthe form of tubular sections each of which has a longitudinal openingtherethrough, said method comprising compacting said product into hollowtubular sections to remove a determinable part of the moisturetherefrom, piling a plurality of said sections in random arrangement oneach other on a supporting surface, forcing a stream of drying airagainst such pile of sections whereby said stream of air travels in atortuous path and passes over and through individual sections in saidpile during its travel through said pile, and continuing such air flowthrough said pile until the average moisture content of said sections isreduced to a predetermined level.

9. A structure in which tubular sections of fibrous wood pulp are to bedried, comprising, in combination, an elongated supporting surface onwhich large piles of pulp sections are to be positioned in randomarrangement for drying, an air duct network in conjunction with saidsupporting surface over which said piles of pulp sections are to bepositioned during drying, means for introducing a supply of drying airinto said duct network for drying said sections piled thereover,conveyor means suspended over said supporting surface for carrying astream of said pulp sections over said supporting surface, and movableselectively locatable means in conjunction with said conveyor fordiverting said stream of pulp sections from said conveyor so that saidpulp sections when thus diverted may drop onto a predetermined portionof said supporting surface, whereby piles of said pulp sections may bebuilt up on preselected locations on said supporting surface for drying;said diverting means comprising a generally V- shaped plow member fordividing said stream of pulp sections and diverting the samesimultaneously from opposite sides of said conveyor means.

References Cited in the file of this patent UNITED STATES PATENTS204,592 Melvin June 4, 1878 488,149 Metzger Dec. 13, 1892 1,256,681French Feb. 19, 1918 1,640,133 Parker Aug. 23, 1927 1,668,446 AndersonMay 1, 1928 1,850,733 Talbot Mar. 22, 1932 2,584,727 Mellen Feb. 5, 19522,608,768 Noel Sept. 2, 1952 2,885,065 Piper May 5, 1959 FOREIGN PATENTS339,563 Great Britain Dec. 11, 1930

1. A METHOD OF DRYING A WET FIBROUS PRODUCT COMPRISING COMPACTING SAIDPRODUCT INTO HOLLOW TUBULAR SECTIONS TO REMOVE A DETERMINABLE PART OFTHE MOISTURE THEREFROM, EACH OF SAID SECTIONS COMPRISING A WALL DEFING ALONGITUDINAL OPENING THERETHROUGH, PILING A PLURALITY OF SAID TUBULARSECTIONS IN RANDOM ARRANGEMENT ON EACH OTHER, AND FORCING A STREAM OFDRYING AIR AGAINST A PLURALITY OF